Adjustable stilts that are strapped onto a workman's shoes to provide him with the necessary elevation to perform various tasks above the floor level have been in use several years. By way of example, the stilts are utilized during the installation of wallboards. The stilts include a pair of rigidly connected vertically adjustable legs defined by upper and lower channel-shaped struts. The bottom of each lower strut is attached to a rubber footpad. The upper ends of the upper struts are strapped to a workman's foot and leg. With heretofore proposed arrangements, a quick-action lock is provided between the upper and lower struts to control the effective height of such struts. The lock includes a plurality of vertically spaced, horizontally aligned holes formed in the struts. These holes selectively receive a pair of stop pegs. The stop pegs are slideably supported within a tube. The tube carries a pair of actuators which extend through slots in the tube to the stop pegs. A compression spring is interposed between the pegs within the tube to constantly bias the pegs outwardly. Each actuator is provided with a finger grip, with the grips being manually urged together to retract the pegs from within the adjustment holes to permit relative vertical sliding movement of the struts to thereby adjust the height of the stilt. Such locking arrangements have proven to be far from satisfactory. The parts of the lock tend to bind, particularly because of their exposure to foreign material, such as dust, present at construction jobs. Because of such tendency to bind, the stop pegs do not always securely lodge themselves within the adjustment holes. This leads to the danger that the lock will suddenly become inoperative causing the workman to risk a dangerous fall. The aforementioned binding tendency also requires considerable squeezing force to retract the stop pegs from within the adjustment holes.